I'm not sure where to post this but I found this on my computer last night.
I have read some forums stating that this is a false positive but those were 2 - 3 ago years.
It was found under
C : \PROGRAM FILES (X86) \DELL \SUPPORTASSISTAGENT\BIN\UPX.EXE
I got this PC from Dell so it came with the Dell Support Assist but I never really registered my PC with them.